The present invention relates to the control of internal combustion engines, and more particularly, but not exclusively, relates to the operator selectable response of an internal combustion engine control system to a throttle control for a vehicle.
In recent years, internal combustion engine performance has been improved through the application of sophisticated control systems. Typically, these systems utilize programmable processing equipment coupled to a number of engine sensors and controls. One result has been the replacement of strictly mechanical engine governors with electronic governing arrangements. For these arrangements, the accelerator pedal of the vehicle is deflected to electronically select an engine operating point corresponding to a desired vehicle speed. The determination of the operating point is usually in accordance with a multivariable control relationship defined by the engine's control system. Consequently, the "feel" of the accelerator pedal to the vehicle driver is influenced by the nature of this relationship.
Generally, the performance or feel of the accelerator pedal varies for a given type of relationship with factors such as vehicle loading, the type of vehicle, driving conditions, and the driver's personal preferences. The variation may be particularly noticeable for heavy-duty vehicles, such as trucks and buses, that often experience large differences in loading. Naturally, it would be desirable to reduce this variation as it may easily become distracting to the driver.
Therefore, there is a demand for a technique to offer a vehicle operator the choice between several different throttle control responses. The present invention meets this demand and provides other important benefits and advantages.